Titanium base alloys



United States Patent TITANIUM BASE ALLOYS Robert I. Jaifee, Worthington, and Horace R. Ogden, Columbus, Ohio, assignors, by mesne assignments, to Rem-Cru Titanium, Inc., Midland, Pa., a corporation of Pennsylvania No Drawing. Application March 23, 1953, Serial No. 344,187

4 Claims. (Cl. 75175.5)

Range, Percent Broad Preferred Aluminum 0. 5-8 1-7. 5 Lead 0. 5-15 1-10 The alloys of the invention may be materially strengthened without undue loss of ductility by controlled additions of the interstitials carbon, oxygen and nitrogen in amounts ranging up to about 0.2% each, the aggregate content not to exceed about 0.6%

These alloys may be made by melt-casting in a cold mold, employing an electric arc in an inert atmosphere, or may be produced in other ways in which the alloy is rendered molten before casting.

The titanium base metal employed may be the product of high purity obtained by the iodide" process described in U. S. Patent 1,671,213 to Van Arkel; or may be the product of commercial purity produced by the magnesium reduction of titanium tetrachloride by the process described in U. S. Patent 2,205,854 to Kroll; or by other procedures producing titanium metal of equivalent purity.

The alloys of the invention possess a substantially allalpha microstructure at room temperature. This results from the alpha microstructure of the titanium at room temperature and the fact that both aluminum and lead, as well as the interstitials carbon, oxygen and nitrogen, all are alpha promoters or stabilizers.

These alloys are further characterized in possessing an ultimate strength at least ten percent in excess of that of the unalloyed titanium base metal, consistent with retention of good ductility. For the broad range of analysis the minimum bend ductilities do not exceed 20T or possess tensile elongations under about 2%. For the preferred range of analysis the minimum bend ductilities do not exceed about 7T, with elongation ranging upwards of about 10%.

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Owing to their substantially all-alpha microstructure, the alloys may be welded without appreciable impairment of ductility in the welded as compared to the non-welded portions. Thus, an alloy containing 4% aluminum and 10% lead, has a minimum bend radius of 3.0T, which is substantially the same as in the unwelded condition.

The following Table I gives mechanical properties of typical alloys according to the invention, in the as rolled and annealed condition, the annealing temperature being 850 F. In the table VHN designates Vickers hardness, while MBR signifies Minimum bend radius.

Table l [Tensile Properties: 1). s. i. 1,000]

(IODIDE Tl BASE) C t n 27 Per; Per- MBR, '1

omposi 10H, can cent Percent (Balance Otfst $5 5 1? Elon- Redue- VHN Titanium) Yield e g gation tion in L T in 1 Area 27 43 40 61 O (l 1Pb-5Al 88 97 12 41 291 a 2.5]? b-GA] 66 78 13 321 (COMMERCIAL PURITY Tl BASE) 51 76 21 51 201 0. 8 0, 8 IUPb-IAI 96 106 14 27 339 l. 8 2. 8

What is claimed is:

1. An alloy consisting essentially of: about 0.5 to 8% aluminum, about 0.5 to 15% lead, up to about 0.2% each of carbon, oxygen and nitrogen, balance titanium, characterized in having an ultimate strength at least 10% in excess of the unalloyed titanium base metal, and a minimum bend radius of not over 20T.

2. An alloy consisting of: about 0.5 to 8% aluminum, about 0.5 to 15 lead, up to about 0.2% each of carbon, oxygen and nitrogen, balance titanium, characterized in having an ultimate strength at least 10% in excess of the unalloyed titanium base metal, and a minimum bend radius of not over 20T.

3. An alloy consisting essentially of: about 1 to 7.5% aluminum, about 1 to 10% lead, up to about 0.2% each of carbon, oxygen and nitrogen, balance titanium, characterized in having an ultimate strength at least 10% in excess of the unalloyed titanium base metal, and a minimum bend radius of not over 20T.

4. An alloy consisting of: about 1 to 7.5% aluminum, about 1 to 10% lead, up to about 0.2% each of carbon, oxygen and nitrogen, balance titanium, characterized in having an ultimate strength at least 10% in excess of the unalloyed titanium base metal, and a mini mum bend radius of not over 20T.

References Cited in the file of this patent UNITED STATES PATENTS 2,669,513 Jaffee et al Feb. 16, 1954 

1. AN ALLOY CONSISTING ESSENTIALLY OF: ABOUT 0.5 TO 8% ALUMINUM, ABOUT 0.5 TO 15% LEAD, UP TO ABOUT 0.2% EACH OF CARBON, OXYGEN AND NITROGEN, BALANCE TITANIUM, CHARACETERIZED IN HAVING AN ULTIMATE STRENGTH AT LEAST 10% IN EXCESS OF THE UNALLOYED TITANTIUM BASE METAL, AND A MINIMUM BEND RADIUS OF NOT OVER 20T. 